This invention relates generally to an inflatable cushion embedded in the upholstery of a motor vehicle seat. The cushion is used to change the contours of the back support and/or the seat cushion. The inflatable cushion is typically placed near the outside edge of the back support or seat cushion in order to facilitate changing these contours.
Such an adjusting device is described in German Unexamined Published patent application DE-OS No. 31 27 303. This device includes two individual cushions embedded within a seat assembly. In order to, in this case, achieve a distinctive wedge shape that causes a good lateral hold for a seat cushion and/or back support. By inflating the cushion located near the edge of the seat more than the cushion that is located near the center, this distinctive wedge shape can be created. However, this air cushion arrangement is relatively expensive and difficult to operate.
Furthermore, it has been contemplated to provide an inflatable cushion on the outside of the seat with a wave-like configuration in order to obtain a gentle slope at the upholstery side facing the passenger. Such an inflatable cushion is described in German Unexamined Published patent application DE-OS 31 25 588. However, this is a cushion structure for the targeted support of the back and is arranged in the center of the back support and consists of several chambers.
It is an objective of the invention to provide an effective lateral support in a simple way and with few expenditures using only one inflatable air cushion, on each side of a seat.
A further objective of this invention is to provide a single inflatable air cushion within the upholstery of a motor vehicle seat to change the contours providing a good lateral support.
A still further objective of this invention is to provide an inflatable air cushion which allows the lateral contours of a vehicle seat to be adjusted to accommodate a wide range of differently shaped people.
These objectives are achieved by providing an inflatable cushion which is embedded in the upholstery of a motor vehicle seat for changing the contours of the back support and/or seat cushion. On the longitudinal side facing the center of the back support or seat cushion the air cushion has a wave-shaped border with intermittent peaks and valleys or troughs.
In the area where the wave crests, these crests being located an equal distance from the opposite edge of the air cushion, there will be a particularly gentle slope with a relatively low wedge height. In the area where the waves are low, there will be a relatively steep slope with a large wedge height. (This can be seen in FIGS. 2 and 3 of the drawings.)
In order to also achieve a large wedge height in an area where the waves are high, the distance of the wave crests to the edge of the cushion is changed. As the volume of the cushion increases, the protruding wave crests 6 are moved closer to the edge of the seat near which the air cushion is embedded. The protruding wave crests 6 being forced to the edge by the forces associated from the wave valleys.
In some embodiments, the wave crests are fixed to the seat element by fastening means. In these embodiments as the volume of air increases within the air cushion, the valley of the waves are moved toward the center of the seat. This provides the wedge shape needed in a slightly different configuration.
Fastening means can also be used to connect the wave crests to each other. This helps to prevent fanning-out of the wave section of the air cushion in an unwanted direction. The fastening also facilitates the correct insertion of the wave section of the air cushion into the recess in the upholstery.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for the purposes of illustration only, a preferred embodiment of the present invention.